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    <title>ShellCheck: SC2252 – You probably wanted `&&` here, otherwise it's always true.</title>
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    <h1>SC2252 – ShellCheck Wiki</h1>
    <a href="https://github.com/koalaman/shellcheck/wiki/SC2252">See this page on GitHub</a>
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    <h2 id="you-probably-wanted--here-otherwise-its-always-true">You
probably wanted <code>&amp;&amp;</code> here, otherwise it's always
true.</h2>
<h3 id="problematic-code">Problematic code:</h3>
<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="SC2252.html#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="bu">[</span> <span class="st">&quot;</span><span class="va">$1</span><span class="st">&quot;</span> <span class="ot">!=</span> foo <span class="bu">]</span> <span class="kw">||</span> <span class="bu">[</span> <span class="st">&quot;</span><span class="va">$1</span><span class="st">&quot;</span> <span class="ot">!=</span> bar <span class="bu">]</span></span>
<span id="cb1-2"><a href="SC2252.html#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="cf">then</span></span>
<span id="cb1-3"><a href="SC2252.html#cb1-3" aria-hidden="true" tabindex="-1"></a>  <span class="bu">echo</span> <span class="st">&quot;</span><span class="va">$1</span><span class="st"> is not foo or bar&quot;</span></span>
<span id="cb1-4"><a href="SC2252.html#cb1-4" aria-hidden="true" tabindex="-1"></a><span class="cf">fi</span></span></code></pre></div>
<h3 id="correct-code">Correct code:</h3>
<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="SC2252.html#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="bu">[</span> <span class="st">&quot;</span><span class="va">$1</span><span class="st">&quot;</span> <span class="ot">!=</span> foo <span class="bu">]</span> <span class="kw">&amp;&amp;</span> <span class="bu">[</span> <span class="st">&quot;</span><span class="va">$1</span><span class="st">&quot;</span> <span class="ot">!=</span> bar <span class="bu">]</span></span>
<span id="cb2-2"><a href="SC2252.html#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="cf">then</span></span>
<span id="cb2-3"><a href="SC2252.html#cb2-3" aria-hidden="true" tabindex="-1"></a>  <span class="bu">echo</span> <span class="st">&quot;</span><span class="va">$1</span><span class="st"> is not foo or bar&quot;</span></span>
<span id="cb2-4"><a href="SC2252.html#cb2-4" aria-hidden="true" tabindex="-1"></a><span class="cf">fi</span></span></code></pre></div>
<h3 id="rationale">Rationale:</h3>
<p>This is not a bash issue, but a simple, common logical mistake
applicable to all languages.</p>
<p><code>[ "$1" != foo ] || [ "$1" != bar ]</code> is always true (when
<code>foo != bar</code>):</p>
<ul>
<li>If <code>$1 = foo</code> then <code>$1 != bar</code> is true, so the
statement is true.</li>
<li>If <code>$1 = bar</code> then <code>$1 != foo</code> is true, so the
statement is true.</li>
<li>If <code>$1 = cow</code> then <code>$1 != foo</code> is true, so the
statement is true.</li>
</ul>
<p><code>[ $1 != foo ] &amp;&amp; [ $1 != bar ]</code> matches when
<code>$1</code> is neither <code>foo</code> nor <code>bar</code>:</p>
<ul>
<li>If <code>$1 = foo</code>, then <code>$1 != foo</code> is false, so
the statement is false.</li>
<li>If <code>$1 = bar</code>, then <code>$1 != bar</code> is false, so
the statement is false.</li>
<li>If <code>$1 = cow</code>, then both <code>$1 != foo</code> and
<code>$1  != bar</code> is true, so the statement is true.</li>
</ul>
<p>This statement is identical to
<code>! [ "$1" = foo ] || [ "$1" = bar ]</code>, which also works
correctly (by <a
href="https://en.wikipedia.org/wiki/De_Morgan%27s_laws">De Morgan's
law</a>)</p>
<p>This warning is equivalent to <a href="SC2055.html">SC2055</a> and <a
href="SC2056.html">SC2056</a>, which trigger for intra-<code>test</code>
expressions and arithmetic contexts respectively.</p>
<h3 id="exceptions">Exceptions</h3>
<p>Rare.</p>
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